07. Molecular Biology & Recombinant DNA Technology [DEFINITIONS]

Question 1

Architecture of Chromosomes

Answer 1

The architecture of chromosomes is the way the DNA molecules are arranged in the nucleoid or nuclear region of the cytoplasm of the prokaryotic cells in the nucleus of eukaryotic cells.

Question 2

Chromosome

Answer 2

DNA of both prokaryotes and eukaryotes are called chromosomes

Question 3

Chromatin

Answer 3

Eukaryotic chromosomes are associated with a large number of proteins called histones that helps to organize the DNA inside the nucleus. This DNA-protein complex is known as chromatin.

Question 4

Heterochromatin

Euchromatin

Answer 4

Lightly packed chromatin is euchromatin.

Tightly packed chromatin is called heterochromatin.

Question 5

DNA Replication

Answer 5

DNA replication is the process which copies a double stranded DNA molecule to produce two identical copies.

Question 6

Gene

Answer 6

A gene is the fundamental physical and functional unit of heredity.

Question 7

Operon

Answer 7

A operon is a group of genes that functions as a single transcription unit comprised of a control region (an operation, a promoter) and structural genes that are transcribed into one mRNA coding for several peptides.

Question 8

Gene Expression

Answer 8

A gene expression is the process by which the information stored in a gene is used to make a functional gene product.

Question 9

Genetic Code

Answer 9

A combination of nucleotides that would be needed to code for one amino acid containing four letters is a genetic code.

Question 10

Transcription

Answer 10

Copying a sequence of DNA into mRNA

Question 11

Initiation of transcription

Answer 11

It is a process initiated at a specific site called the promoter where the one strand of double stranded DNA acts as template.

Question 12

Elongation of transcription

Answer 12

This is the process where RNA polymerase starts adding complementary ribonucleotides against the template DNA by RNA polymerase in the 5’ to 3’ direction until reaching the production termination site.

Question 13

Termination of transcription

Question 14

Translation

Answer 14

Converting the information in mRNA to a sequence of amino acids

Question 15

Promotor

Answer 15

The process of transcription is initiated at a specific site called promotor

Question 16

Transcription Termination Site

Answer 16

RNA polymerase enzymes can start adding complementary ribonucleotides against the template DNA. RNA polymerase continues to add nucleotides in 5’ to 3’ direction until it reaches the transcription termination site.

Question 17

Transfer RNAs (tRNA)

Answer 17

Ribosomes read the message written as a sequence of triplet codons in an mRNA and translate it into a sequence of amino acids in a polypeptide with the assistance of transfer RNAs (tRNA)

Question 18

Initiation of Translation

Answer 18

The first step in initiation is binding of small subunit of ribosome to mRNA and to the initiator tRNA which carries methionine as the first amino acid. Then, the two subunits of the ribosome combine to form the functional ribosome.

Question 19

Elongation of translation

Answer 19

This is a stage where amino acids are added to the C- terminus of the growing polypeptide chain by peptide bonds, one after the other governed by the triplet codons.

Question 20

Termination of translation

Answer 20

When the mRNA moves, it finally aligns one of the stop codons: UAG, UAA, or UGA with A site

Question 21

Polyribosomes / Polysomes

Answer 21

mRNAs translated actively are associated with multiple ribosomes attached to a string to mRNA, forming polyribosomes or Polysomes

Question 22

Polyribosomes / Polysomes

Answer 22

mRNAs translated actively are associated with multiple ribosomes attached to a string to mRNA, forming polyribosomes or Polysomes

Question 23

Mutation

Answer 23

An alternation of the nucleotide sequence of the genome of an organism is a mutation

Question 24

Isolation of DNA

Answer 24

Gene technology beings with the isolation of the target DNA sequence from the total genome of the donor cells.

Question 25

DNA Probe

Answer 25

A DNA probe is a fragment of single stranded labelled DNA used to detect the presence of complementary nucleic acid sequences by hybridization.

Question 26

Labelling

Answer 26

Labelling is a modification of the DNA strand in such a way that it gives a signal which enables the detection of that DNA strand.

Question 27

Southern Blotting

Answer 27

This is a process where the denatured bands on the gel need to be transferred to a nitrocellulose or nylon filter membrane

Question 28

Recombinant DNA Molecules

Answer 28

DNA molecules made by laboratory methods of genetic recombination which brings together DNA from different sources, creating sequences that are not found naturally.

Question 29

Recombinant Vector

Answer 29

When the vector is carrying the foreign DNA, it is a recombinant vector.

Question 30

Transformation

Answer 30

The direct uptake of exogenous DNA from the surroundings of a host through its cell membrane and incorporation, resulting in a genetic alteration

Question 31

DNA Libraries

Answer 31

DNA libraries are a collection of microbial cultures each propagating a different fragments of a total genomic DNA which are cloned in a population of identical vectors.

Question 32

Restriction Maps

Answer 32

A restriction map is a diagram showing the position of each restriction site with respect to each other and the distant between these sites.

Question 33

DNA Sequencing

Answer 33

DNA sequencing is a process to determine the precise order of these bases in a DNA molecule

Question 34

DNA Fingerprinting

Answer 34

The unique set of genetic markers of an individual makes its DNA fingerprint or genetic profile.

Question 35

Polymerase Chain Reaction - PCR

Answer 35

PCR is used to copy sequences of DNA in vitro, mimicking the DNA replication using the raw materials such as deoxyribonucleotide triphosphate (dNTPs) including four deoxyribonucleotides (dATP, dGTP, dTTP, and dCTP)

Question 36

Genetically Modified Organism (GMO)

Answer 36

The hose with the extra trait introduced by genetic engineering techniques is called a genetically modified organism (GMO)

Question 37

Cartagena Protocol

Answer 37

This is an international agreement signed on may 15th of 2000 in Montreal, Canada to protect biological diversity from potential risks caused by genetically modified organisms or living modified organisms LMOs) created as a result of modern biotechnology.